  //动态操作动画的逻辑
  export const getKeyframes = (keyframesName) => {
    //通过定义的动画函数名来查询函数
    let styleSheet = document.styleSheets //获取所有样式表
    let animation = {} //定义一个animation来装获得的值
    for (let i = 0; i < styleSheet.length; i++) {
      //遍历循环获取styleSheet
      for (let j = 0; j < styleSheet[i].cssRules.length; j++) {
        //遍历循环获取styleSheet[i].cssRules
        //判断样式名字是否为CSSKeyframesRule
        if (styleSheet[i].cssRules[j].constructor.name === 'CSSKeyframesRule') {
          //再判断此时这个动画函数名是否为传入的值
          if (keyframesName === styleSheet[i].cssRules[j].name) {
            //获取此时的cssRules，index，和styleSheet
            animation.cssRules = styleSheet[i].cssRules[j]
            animation.index = j
            animation.styleSheet = styleSheet[i]
            return animation //返回获取的animation
          }
        }
      }
    }
  }